This game has worked well for me as a warmup activity to teach kids here in Japan vocabulary. I got the idea from my Japanese teacher back in college. First write the vocabulary that you want to teach on the board. Then write the same vocabulary in their native language. Make sure too spread the words out so that the translations are not too close together. If you want to prepare for this game before class, just write the words on some big cards of pieces of paper and then put them on the board.

Now divide the class into two teams (if the class is really big then divide it into three or more) and give each group a different colored piece of chalk or marker. Each group stands in a line in front of a side of the board. The first person in line from each group will go first. Then all you have to do is call out the English word, but instead of circling the English word they will circle the corresponding word in their native language. When you call out a word in their native language, they will have to circle the english word. For example, in the case of Japanese if I say "neko" they would circle the English word "cat" and when I said "cat" they would circle the Japanese word.

You can make this really fun by just saying something silly every now and then. The kids will rush to find the word without realizing that what you said isn't a word in either language. I've had a lot of success with this game in teaching new vocabulary, so if you feel like it give it a try and it may just work for you as well.